Automatic telephone system.



R. S. WILBUR.

AUTOMATIC TEL EPHONE SYSTEM.

APPLICATION FILED JULY 11; 1910.

Patented Oct. 26, 1915.

I0 SHEETSSHEET I. I

AT TQR N EYS R. S.- WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED .IULY H. I9I0.

Patented act. 26, 1915.

I0 SHEETS-SHEET 2- INVENT R. s. WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY II. [910.

26, 191 10 SHEETS-SHEET a.

Patented Oct mwma INVENTOR AmRNEYs R. S. WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLBCATiON FILED JULY 11. 1910.

5 11. 94 IT E 6M. m mm d8 0 MI W on P W N WVENTOR ATTQ RN EYS R. S.WILBUR.-

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY H. 1910.

LWWMW. Patented Oct. 26, 1915.

10 SHEETSSHEET 5.

INVENTOR ATTOR/VE w R. S. WILBUR. AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY 11, I910.

Patented 001;. 26, 1915.

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R. S. WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATTON FILED JULY H. Wm.

10 SHEETS-SHEET T.

Patented Oct. 26, 191.

B. S. WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY 11. 1910.

Patented Oct, 26, 1915.

l0 SHEETS-SHEET s.

IIVl/ETVTOR R. S. WILBUR.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY H. 1910.

MWWWH Patented; 00. 26, 1915.

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INVENTOR (Z 1% v R k '7 R. S. WILBUR. AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY II 1910.

Patented 00$. 26, 1915.

I0 SHEETS-SHEET 10.

INVENTOH WITNESSES:

Specification of Letters Patent.

JERSEY, ASSIGNOR, BY MESNE ASSIGEMEN'IS, OF CHICAGO, ILLINOIS, ACORPORATION OF AUTOMATIC TELEPHONE SYSTEM.

Patented Oct. 26, 1915.

Application filed July 11, 1910. Serial No. 571,344.

To all whom it may concern.

Be it known that I. RAY S. lVILnUu, a citizen of the United States,residing at. Jersey City, in the county of Hudson and State of NewJersey, have invented a certain new and Improved Automatic TelephoneSystem, of which the folloiving is a full, clear, concise, and exactdescription, reference being had to the accompanying drawings, forming apart of this specification.

My invention has for its object to accomplish the connection ofsubscribers to a telephone exchange system by means of automaticapparatus at the exchange adapted to be actuated by the subscriberinitiating the call, without the intervention of an operator at theexchange.

My invention is an improvement over automatic telephone systemsheretofore employed in that the first selector switch usually associatedwith each telephone line is re placed by a comparatively simple trunkfinder which is automatically operated upon the removal of the receiverat the calling station without a further act on the part of the callingsubscriber to select an idle trunk circuit extending from the callingline to the first selector switches employed in setting up theconnection to the called subscriber. By my invention the number of firstselector switches required is the same asthe number of second selectorswitches and third selector switches and is preferably such that eachdigit of a number corresponding to a called subscriber is provided withten of these switches or in other words that one hundred of each of theselector switches mentioned are required. This provides that each digitmay be selected over any one of ten paths or trunks until the connectorswitch is reached, the latter serving to establish con nection betweenthe last selector switch. employed and the called subscriber.

By my invention the apparatus employed in connection with each selectorswitch automatically out be from the built up connecting circuit as theconnection proceeds toward the called subscriber, and when theconnection is effected the only paths con 'nected across such connectionare those required to furnish battery to the connected subscribers fortalking purposes. In other words, the resulting connection is theequivalent of the mostctlicient form of connecting circuits known inconnection with the operat1on of manual exchanges which. ischaracterized by conductors at the exchange separated either bycondensers or the windings of a repeating coil in such a manner thateach section'of the circuit may be separately supplled with battery fromthe exchange for talking purposes and furthermore that no other windingsthan those employed in the supply circuits are connected duringconvertion across the conductors establishing such talking connection.

By my invention the number of actuating those shown in the accompanyingdrawings being of the well known form in which wipers are adapted to bemoved vertically by succeeding current impulses, opposite rows ofcontacts corresponding to the digits of the number wanted, and in whichwhen the wipers come opposite the proper rows or banks of contacts suchwipers may be moved angularly in engagement with the contacts until anidle trunk is found which is in connection with the contacts selected bythe wipers.

My invention further consists in a means for restoring the selectingapparatus to its normal condition at the termination of a conversationwhich apparatus operates over a third wire of each trunk involved in theconnection beginning at the first; selector switch and'disconnectingeach of the succeeding switches one after the other in a forwarddirection through the connection.

The several drawings illustrating the invention are as follows:

Figure 1 is a side view of an auxiliary switch or mechanism used inconnection with the main connecting switch; Fig. 2 is a top view of theswitching mechanism shown in Fig. l; Fig.6 is a view of the auxiliaryscrewed into the cores of the coils.

switchingmechanism taken from the opposite side from that shown in Fig.1 and shows-the armature operated by the lower magnet; Fig. at is a viewtaken from the lower end of the parts of the auxiliary switchingmechanism shown Fig. 1; Fig. .3 is a diagrammatic view of the resultsaccomplished by the auxiliary switching mechanism shown in Figs. 1 to tinclusive, the convention employed in Fig. 5 being similar to thatemployed throughout the description of the apparatus below; Fig. 6 is afront view of one of the main switches; Fig. 7 is s a side view of themechanism shown in Fig. 6; Fig. 8 is a top view of the trunk finder;Fig. 9 is a sectional View taken along the line a'a of Fig. 8, and showsthe method of carrying the wipers on the rotary shaft of the trunkfinder and the manner in which the wipers engage the cont-acts of theswitching mechanism; Fig. 10 is a diagrammatic drawing of a' substationcircuit and shows in diagrammatic perspective view a calling mechanismused to control the circuits of the automatic connecting switches at theexchange; Fig. 11 is a diagrammatic circuit drawing of the connectionsemployed in the trunk finder switch shown in Figs. 8 and 9; Fig. 12 is adiagrammatic circuit drawing of a first selector switch; Fig. 13 is adiagrammatic circuit drawing of a second selector switch; Fig. 14.- is adiagrammatic circuit drawing of a connector switch; Fig. 15 is adiagrammatic circuit drawing similar to Fig. 11 of a trunk finder,switch connected with the called subscriber; and Fig. 16 is adiagrammatic circuit drawing ofthe apparatus located at a calledsubstation which is involved in establishing a talking connection.

Referring to Figs. 1, and 4, the construction of the auxiliary switch isas follows; Coil 1 is the release magnet and coil 2 isthe escapementmagnet, both being tastened to a heel piece 3 by screws 4 and 5 (oil 1has an armature 6 pivoted on the heel. piece 3 at 7. To the armature (ithere is fastened an arm 8 which engages a hook 9 on a spring 10. Aspring 11 is provided to cause the armature 6 to move away from the coreof the coil 1 when such armature is released from the hook 9 on thespring 10. The armature 6 carries a set ot'wipers 12, 13 and 14, asshown in Fig. 2. The wiper 12 engages the contacts 15, 16 and 17 when inits different positions and the Wipers 13 and 14;

. engage similar contacts disposed below the contacts 15; 16, and 17.-The wiper 12 is divided into two parts one of which engages the cbntacts15, 1G. and 17, while the other engages the segment 18, as shown in Fig.2. As a result segment 18 is placed in electrical connection with eitherthe contact 15, 16 or 17 depending upon the position of the armsture 6.The wipers 13 and 1 1- are construct ed in a manner similar to thatdescribed for the wiper 12. An armature 19 is provided for theescapement magnet .3 pivoted to the heel piece 3 at the point 20. Thearmature 19 is connected by an insulating stud 21 with the spring 10 andwhen the magnet 2 is energized, the armature 19 is attracted to the polepiece 22, thus moving the spring 10 to release the'arm 8 from the hook Jcarried by such spring. When thus released, the spring 11 moves thearmature 6 outwardly away from the magnet 1 and causes the wiper 12 tomove toward the contact 16. Before the wiper 12 leaves the contact 15 itis stopped by the engagement of the hook 22 on a spring 23 carried bythe armature 1S) and extending through an opening in the arm 8, as shownat 2% in Fig. 4. When the magnet 12 is deenergized the arn'iature 1.)drops back to normal position and allows the arm 8 to move intoengagement with the stop 24 carried by the spring 10 and at the sametime allowing the wiper 12 to leave the contact'lli and rest upon thecontact lo. Another upward. and downward motion of the armature 19causes a similar operation between the stop 2%" on the spring ll) and.the hook 25 on the spring 23, thus permitting the wiper 1:2 to leave thecontact in and to rest upon the contact 17 under the action or thespring 11. When the magnet 1. is energized, it attracts the armature l)and moves the arm 8 to again engage the book 9 and the wipers 12, 13 and'14.- are returned to their normal contacts where they remain until thearmature 19 is again oporalod as described above. An adjusting screw 20is provided in the heel piece 3 to limit the out ward motion of thearmature (i so as to prevent motion of the wipers 1Q, 13 and 1-l beyondthe contact 17.

In Fig. 5 the pivotal point 1.8 represents the segnwut 13 above rclcrrcdto. while the switch 12 and the contacts 15. 1(1 and 17 representdiagrammatically the wiper '12 and the contacts 15.16 and 17 abovereferred to. Figs. (3 and 7 show one of the main automatic switchesemployed in eltecting the connection between :1 called and the callingsubscriber. As shown in these figures, a shaft Q'Tcarries two ratchets28 and 29 adapted to move the shaft in a rotary and a vertical directionrespectively. The shaft 27 is carried from the bracket 30 by twobearings 31 and 32. A magnet 33 is provided with a heel piece 34: andboth are fastened to the bracket 30 by a screw 35. The heel piece 3t hasan armature 36 pivoted to it at 37, which pivot is similar to a pivot 38shown in connection with the magnet 39. The armature 36 has an arm 40extending toward the shaft 37 to which arm is pivoted the pawl 41 whichengages the ratchet 2%). When the magnet 33 is enering over the teeth ofgized, it attracts the armature 36, which in turn lifts the pawl 41 andthereby the shaft 27 by means of the ratchet 29. After the shaft hasbeen lifted one step, it is held'in this position by a pawl 42 which isprovided with an extending arm 43 engaging the ratchet 29. As a result,when the magnet 33 is dei nergized, the shaft 27 does not drop back, butis held in the position to which it has been actuated and the pawl 41moves dmvnwardly and into engagement with another tooth of the ratchet29 ready to lift the shaft 27 another step when the magnet is againenergized. The bracket 30 has also secured to it by a screw 44 a rotarymag- ,net, the part 46 shown in F 7 being the heel piece thereof. Therotary magnet is provided with an armature 47 pivoted to the heel piece46 and to the armature 47 there is secured. an arm similar to the armabove described in connection with the armature 36. The arm secured tothe armature of the rotary magnet has pivoted thereto a pawl 48 whichengages the ratchet 28. The operation of the armature 47 of the rotarymagnet movesthe pawl 48 to rotate the shaft 27 which is held in theposition to which it is advanced by means of an arm 49 extending fromthe pawl 42 into engagement with the ratchet 28. A support '50 isprovided in connection with the ratchet 29, which support normally liesin a vertical groove in such ratchet and necessitates motion of theshaft 27 first in a. vertical direction, after which motion the support50 may enter one of the grooves of the ratchet to permit rotary motionof such shaft, thus serving to support the shaft in the verticalposition to which it has been moved while the pawl 42 .is pass theratchet 28 during rotary motion of the shaft. The pawl 42 is supportedin suitable bearings in the brackets 51 and 52. A stop 53.is carried bythe bracket 30 to limit the motion of the pawl 41 so that the shaft 27may be raised one step at a time. A similar stop 54 is pro vided to solimit the motion of the pawl 48 that the shaft 27 may be rotated but onestep at a time by means of the ratchet 28.

Assuming now that the shaft 27 has been displaced several steps in avertical direction and several steps in a rotary direction, the nextoperation is that'of releasing or returning the shaft to its normalposition.

This is accomplished. by means of the magnet 39 which is secured t aheel piece and to the bracket 30 means of a screw 56. The magnet 39provided with an armature 57 pivoted to the heel piece as indicated andprovided with an arm 58 eX- tending toward the shaft 27. This arm restsback of the arm extending from the pawl 4-2, as a result of which anoutward movement of the arm 58 moves the pawl 42 upon its pivotalsupports and moves the arms 43 board.

means of screws 91 and 49 from engagement with the ratchets 29 and'28respectively. The arm 58 has secured to it a member 60 consisting of twoportions, one of which 61 rests normally back of the tail 63 on the pawl48, while the other portion 62 rests normally Back of the tail 64 of thepawl 41. When the armature 58 is moved outwardly therefore, it servesnot only to disengage the arms 43 and 49 of the pawl 42 from theratchets 29 and 28 respectively, but also to disengage the pawls 41 and48 from such ratchets and to leave the shaft free. to be returned tonormal position which is accomplished by means of a spring located inthe cup 65 and by the action of gravity. The spring rotates the shaftbackwardly to its normal position at which time the support 50 is inline with the groove in the ratchet 29 and gravity causes the shaft tothen drop to its normal position.

The complete switch is supported on the back frame or support 66 whichholds the switchesthat make up a complete switch- The two posts 67 and68 are screwed into the frame 66 while the bracket 30 is provided withclearance holes for the posts so that the switch can be removed from thebank support by taking off the nuts 69 and 70 from the endsof the posts67 and 68. The posts 67 and 68 support the banks of contacts adapted tobe engaged by'suitable wipers carried by the shaft 27, which contacts'and wipers are not here shown since they may be constructed in a mannerwell known in the art and do not constitute an essential part of thisinvention.

The trunk finder switch is constructed as indicated iirFigs. 8 and 9 inwhich a ratchet wheel 71 is supported by a shaft 72 suitably mounted inbearings in the switch base 73 and in a bridge 74 secured to the base byscrews 75. Vipers 77, 78, 79 and 80 are carried but insulated from theshaft 72 by an insulating bushing 81, such wipers being separated fromeach other by insulating washers 82, 83, 84, 85 and 86. These washersand wipers are all clamped securely in position by the washer and nut 87and 88. Each of the wipers 77, 78, 79 and 80 is provided with a feederspring, the feeder for the Wiper 77 being shown in Fig. 8 at 89. Thesefeeders make contact with circular portions of the corresponding wipersdisposed around the shaft 72 and are supported by a block of insulatingmaterial 76 secured to the bridge 74 by the clamping plate 90 by Thebase 92 used to support the bank of contacts adapted to be engaged bythe wipers has two arms 93 and 94 grooved on their edges at 9,5 and 96so as to slide on the base 73 and thus line up the base 92 with theswitch base 73 to properly center the contacts. The bank base 92 hassecured thereto by means the three supports 97, 98 and 99, the bank 100,Co n tacts1 1, 1 and 108; illustrate the method of arranging thecontacts of the bank 160 with which the wipers 7 7, 7 7 and, 0 makecontact. For the particular system de= scribed in the presentspecification, it is to be understood that there are to be elevencontacts in each row and three difierent rows, The shaft 72 is held inits normal position by a. spring in the cup 101 which also serves toreturn it to normal position after ithos een rotated and released. Theratchet wheel 71 carries an insulated post 1 5 which engages the spring106 and normally causes such spring to make contact;

. with a spring: 107. 0116 rotary step of the ratchet wheel 71 issuiiicicnt t cause the spring lOG to break contact with the spring 107and to make contact with the spring 108. These springs are called 063normal springs.

' To the base .73 there is secured the heel piece as .a pawl foropera-ting the ratchet wheel 71,- ;Whcnthe coil 112 is energized, the

armature 1.15 is attracted and thus the arm 116 is moved. outwardly,bringing the pawl 117into engagement with another tooth of the ratchetwheel 71. When the coil 112 is doinfcrgized. the spring 118 engaging thearm 11 at the point 119 advances the ratchet wheel 71 0116 5681 Aretaining pawl 1520 is provided to engage. the teeth of the ratchetwheel .71, to hold it in the position to which the iawl 117 has moi cdit. A hecl piece 1'21 is secured to the base 73 by screws 1'22 and 126.This heel piece has secured theret a coil 12% by moons of a screw 125.This hcol piece has formed thereon two curs which pii'otally suiport thearmature 127 of the coil 12%; The armature 1'27 has cistendingthcrefromback of the two pawls 117 and 120 an arm 128, so disposed that when thecoil 121 is energized, the attracti n f'thc armature 1.27 moves the arm128 to lift the pawls 117 and llOaway from the ratchet wheel 71, thusleaving it free to be rotated to nornnil'position by the operation ofthe spring in thecnp 101.

As shown in Fig, 10, the mechanism used at a calling station isindicated diagrammatically by a disk 129 adapted to be 0perated by a.rcmovgiblc handle 130 which may be inscrtedin any one of a plurality ofholes 181 to rotate the disk varying amounts, at the end of whichrotation the lower end of thehandle projecting below the disk 199 ongages ajixed step 132. After any such rotuition when the-handle 136isrele'esd, suita le spring mechanism not shown serves to rotate the disk129 to its normal position, at the some time rotating the make and breakmechanism consisting of a metal plate 133 provided with an insulatingsector 13% upon opposite sides of which are disposed the contact springs135 and 136 supported by and insulated from the frame of the sendingmechanism Asa result, when the springs 135 and 136 rest upon the metaldisk, the conductors connected with such springs are electricallyconnected, together and when the insulating sector 131 rests between thesprings 135 and136, the circuit through the wires connected with suchsprings is inter rupted. The spring 136 is connected by the wire 137with one terminal 138 of the substation nppn 'utus, the other spring 135being connected with one terminal of the transmitt r 139, the otherterminal of which is connected by Wire 1 10 with :1 spring 111 oi theswitch 142. The spring 143 of the hook Switch is connected by wire 141with one terminal 115 of the magnet 116, the purpose of which magnet isto be explained. The other terminal of this magnet 117 is con nectcd bywires 148 and 149 with the terminal 150 of the substation inpurutus. Thespring 151 of the hookswitcli is con.- nected by wire 152 with oneterminal of the receiver 153, the other terminal of which is connectedby wire 154: with wire 1.55 connocting one terminal of the ringer 156with one terminal of the condenser 157. The other terminal of thecondenser. is connected by wire 158 with wire 119, The other terminal ofthe ringer is connected by wire 15%) with the spring; 160 of the hookswitch, The terminals 156 and 1 8 are connected respeclively. with theline conductors 161 and 16;.

it is thought that in View of the description of the apparatus alreadygiven and the diagrammatic nature of the remaining: drawings. that theconstruction and operation of the apparatus may be readily inn erstoodby following through the operation oi the apparul'us in setting up aconnection without describing in detail the circuit connectionscinploycd.

Assuming that the substation shown in Fig. 10 desires to cll'cct aconnection with the substation shown in Fig. 16, and that the trunkfinder shown in Fig. 11, the scloctor switches shown in Figs. 12 and 13the connector switch shown in Fig. 11, and the trunk finder switch shownin Fig. 15 are involved in making the connection, the operation is asfollows: The subscriber at the substation shown in Fig. 10 removesreceiver 153 from the hook switch 112. thus closing the followingcircuit: ground 168, wire 16-1, wire 165, coil 166, wire 167', spring168, spring 169, wire 176, wire 171, contact 172, wiper 173, wire 1%,spring 175, spring 176, wire 177, wire 178, conductor 161, ter- 169,wire 170, wire 212,

Ininal 150, wire 149, wire 14-8, coil 1416, Wire 144, spring 143, spring151, spring 111, wire 110, transmitter 139, wire 179, spring 135, metalplate 133, spring 136, wire 137, terminal 138, wire 162, wire 180, wire181, spring 182, spring 183, wire 181, wiper 185, contact 186, wire 187,wire 188, coil 12%, wire 190, spring 191, spring 192, wire 193, wire 191to battery 195, thus closing a' circuit from ground 163 through coils12-1 and 166 to battery 195. This How of current will energize coil 166and cause its armature to operate spring 189 and the spring 196. Coil121- is low wound and has a heavy spring tension on its armature,therefore it will not operate spring 197. When spring 1.96 is broughtinto contact with spring 198 by the movement of the armature for coil166, the following circuit will be closed: ground 163, wire 161, wire199, wire 200, spring 198, spring 196, wire 201, coil 112, wire 202 tobattery 195. When the motor magnet 112 is energized, the followingcircuit is closed: ground 163, wire 16-1, wire 199 and wire 203, spring201, spring 189, wire 205, wire 206, coil of the cut-011' relay 20?,wire 208, Wire 191 to battery 195, thus energizing cut-01f relay 207which is a slow acting relay having av copper shield over its core.Therefore, while the motor magnet 112 ismoving wipers 185, 173 and 209over the bank contacts, relay 207 will cause its armature to operatesprings 183, 175 and 191, thus opening the two lines 180 and 178, at'thesame time keeping the wipers 185 and 1" con'nectionswhile they arepassing over busy contacts or trunks.

Through the medium of mechanism not shown in the drawing, the magnetcoil 1.1.6 controls the movement of the impulse-sending device so thatits dial 129 and its contact making segments 133 and 13 1 cannot berotated for the purpose of sending impulses except during the periodwhen battery from the central otiice is applied to the limbs 161 and 162of the telephone'line. This renders it impossible for a subscriber touse his interrupting device during the period of energization of therelay 207, which relay is energized as above described during theselective movement of the wipers carried by the shaft 210. If all thetrunks with which the wipers of the shaft 210 may connect are busy, the,relay 207 will remain actuated and the calling subscriber will be unableto send any impulses over the line.

Spring 191 being operated will be in contact with spring 211, thuscompleting the following circuit: ground 163, wire-"16.1, Wi re 165,coil 166, wire 167, spring 168, spring spring 211,-spring 191, wire 190,coil 12-1, wire 188, wire 213, wire 211 to wiper 209. Therefore, ifwiper 209 finds battery on the contacts over which it is passing, therelay 166 will be energized (3 free from any ca use springs 231 and 232to move.

and as the circuit for relay 166 passes through the contacts 168 and 169which are controlled by the motor magnet 112, it is ap parent that eachtime the motor magnet is energized, it will denergize relay 166 whichwill in its turn deiinergize motor magnet 112.

This alternate action will be continued as long as wiper 209 findsbatter on the con tacts over which it passes, thus stepping the wipers185, 173 and 209 over busy contacts. By busy contacts is meant contactsthat are in use at some other switch connected in multiple with theswitch shown in Fig. 11.

To show how one of the switches shown in Fig. 11 may make another ofsuch s tches with which it is multiplied busy by being in use, assumethat wiper 209 has stopped on a certain contact, the correspondingcontacts of the other switches will be made busy by the followingcircuit: wiper 209, wire 211, wire 213, wire 188, coil 121, wire 190.spring 191, spring 192, wire 193, wire 191 tobattery 195. The springs191 and 192 are in engagement at this time since the magnet 112 hasceased to advance the wipers 185, 173 and 209. subscriber cannot breakin upon the conversation of another subscriber who has established aconnection making busy certain of the contacts of the trunk finderswitch.

Assume now that wipers 185, 173 and 209 have been moved to contacts 215,216 and 217, thus extending the lines 180 and 178 through to trunks 218and 219. Trunk 218 is connected through wires 220 and 221, coil of relay223 and wire 221 to battery 225. Trunk 219 is connected through wires226 and 227, coil 228, and wire 229 to ground 230, thus closing thecircuit through the telephone Fig. 10 to energize operating relay 223. IWhen relay 223 is energized, it will Spring 2331 will break contact withsprin 233 and make contact with spring 2341, thus closing a circuit fromground 235 through wire 236, springs 231 and 234, wire 23?, relay 238,wires 239 and 240 to battery 211. This will energize slow relay 238 andcause spring 2-12 to break contact with spring 243 and make contact withspring 211.

Assume now that the line at the telephone is opened for an instant asoccurs in sending selecting impulses from the calling substation,allowing relay 223 to be denergized, thus causing spring 231 to makecontact with s n-ing and spring 232 to make contact with'spring 215.Relay 238 being slow will remain in operated condition for the instantthat relay 223 is denergized, thus causing a current flow from ground235, through Wire 236, spring 231, spring 233, wire 246, spring 242,spring 244, wire 247, wire 24:8, Wiper 249, wire 250, vertical magnet251, wire 252 to battery 241. At the same time a second circuit isclosed from This provides that one lifted the shaft 267 five steps.

wire 247 to wires 253, 254, spring 245, spring 232, wire 255, relay 256,wire 257, wire 240 to battery 241. Thus, during the instant that thetelephone circuit is opened, vertical magnet 251 and relay 256 willreceive a momentary flow of current.

Relay 256 being a slow relay will remain in operated condition duringthe continuance of a series of recurring impulses coming one after theother in rapid succession. While relay 256 is in operated condition,spring 258 is in contact with spring 259, thus causing a current flowfrom ground 260 through wire 261, spring 258, spring 259, wire 262,relay 263, wire 264, wire 265 to battery 266, thus energizing relay 263.Assume now that live impulses were sent over the line and verticalmagnet 251-has At the cessation of these impulses relay 256 allowsspring 258 to break contact with spring 259 and make contact with spring268, thus deenergizing relay 263, which, being a slow relay, will stayin operated position for an instant allowing a flow of current fromground 260, through wire 261, spring 258, spring 268, wire 269, spring270, spring 271, wire 272, wire 273, wiper 274, contact 275,

wire 276, wire 277, rotary magnet 278, wire 279, wire 224 to battery225. At the same time a branch circuit is closed from wire 276 asfollows: wire 280, coil 281 of-escapement magnet 282, wire 283,wire-284,

battery 266, thus causing the switch to ro-' tate shaft 267 one step andto prepare the .escapement of the auxiliary switch to take place, or inother words to allow wipers 249, 274 and 285 to move to contacts 286,and 288. Assuming, however, that wiper 289 finds ground on contact 290,the following circuit is established: grounded contact 290, wiper 289,wire 291, wiper 285, contact 292, wire 293, wire 294, coil of escapementmagnet 282, wire 29.6, wire 284 to battery 266, thus keeping escapementmagnet 282 energized as long as wiper 289 finds ground on the bankcontacts. The following circuit is closed in parallel with the circuitlast traced: wire 293, wire 297, spring 298, spring 299, wire 300,spring 301, spring 302, wire 303, relay 263. wire 264, wire 265 tobattery 266, which will energize relay and close the contact betweensprings 270 and 271, thus energizing rotary magnet 278, as abovedescribed, which will open the circuit to relay 263 because it breaksthe contact between springs 298 and 299. This alternate action of therelays 278 and 263 continues as long as there is ground on wiper 289. Orin other words, the shaft will be rotated until Wiper 289 ceases to findground that at the same time wipers 249, 274 and 285 are moved intoengagement with contacts 286, 287 and 288. Now when relay 223 isoperated, instead of operating vertical magnet 251, the followingcircuit is closed: ground 235, wire 236, spring 231, spring 233, wire246, spring 242, spring 244-, wire 247, wire 248, spring 249, contact286, wire 308, wiper 304, contact 306, wire wire 310, wiper 311, contact312, wire 313, wire 314, relay 315, wire 316, to battery 317, thusenergizingrelay 315 which will close the following circuit: ground 318,wire 319, spring 320, spring 321, wire 322, spring 323, spring 324, wire325, vertical magnet 326, wire 327, wire 328 to battery 317. Thus shaft329 can be stepped up as desired. When these vertical impulses cease,there will be a rotary impulse as described for Fig. 12 which willoperate rotary magnet 330 and esecapeinent magnet 331 as follows: ground260, wire 261, spring 258, spring 268, wire 269, spring 270, spring 271,Wire 2712, wire 273, spring274, contact 287, wire 332, wiper 305,contact 307 wire 333, wire 334, wiper wire 336 and wire 337, rotarymagnet 330, wire 338, wire 328 to battery 317 There is also closed atthe same time a as fdllows: wire 336, wire 339, wire 340, coil.

This gives the wipers on shaft 329 one rotary step and in case wiper 345finds ground it will take another rotary step as follows: ground onwiper 345 will keep escapenient magnet 331 energized by the followingcircuit: ground on wiper 345, wire 346, wiper 347, contact. 348, wire349, coil 350, wire 351, wire 343 to battery 344. This circuit is closedas long as the wiper 345-finds ground upon the contacts 352 and thefollowing circuit is closed through relay 315, ground 353, wire 35-1.wire 355, spring 356, spring 357, wire 358, spring 359, spring 360, wire361. wire 314-. relay 315. wire 316, to battery 317.

Relay 315 being energized will energize rotary magnet 330 as follows:ground 318. wire 319. spring 320. spring 321. wire 322. spring spring362. wire wire 337, rotary magnet 330, wire 338. wire 328 to battery317. The energization of rotary magnet 330 will open the energizingcircuit oi relav 315, therefore this alternate action of the relays 330and 315 will take 363, wire 339. l

341 of escapement magnet 331, wire 342,

wire 343 to battery 344.

wire 383, wire 384, wire 385 to battery 383. Thus shaft 386 can hestepped up as desired and an impulse sent over line 387 will en-.

ergize escapement magnet 388 as follows: ground on line'387, wire 389,spring 390. spring 391, wire 392, coil 393 of escapement magnet 388,wire 394, wire to battery 396. This impulse energizing and definergizingthe escapnieut magnet will allow wipers 380, 397, 398 and 399 to pass tocontacts 400, 401, 402 and 403. The next set of impulses sent overlire376 will operate the rotary magnet 404 as follows: from the ground 011the wire 248 as caused by the action of the relay 223, through the trunkconductors connected therewith, to wire 37 6, springs 377 and 378, Wire379, wiper 380, contact 400, wire 405, rotary magnet 404, wire 406, wire407, wire 384, wire 385 to battery 383. Thus as many rotary steps asdesired can be taken and another impulse over line 387 will againenergize escapement magnet 388 and allow wipers 380, 397, 398 and 399 toescape to contacts 408, 409, 410 and 411. If, however, the subscribercalled is busy, or in other words wiper 412 is resting on a groundedcontact at the time this impulse is made, the following circuit isclosed which will prevent the wipers 380, 397, 398 and 399 fromadvancing: ground on wiper 412, wire 413, wiper 399, contact 403, wire414, spring 415, spring 416, wire 417, wire 418, coil419, wire 420, Wire395 to battery 396. At the same time 'a circuit is closed in parallelwith the circuit last traced as follows: the junction of Wires 417 and418, wire 421, wire 422, relay 423, wire 424, wire 407, Wire 384, wire385 to battery 383, thus closing contact between springs 425 and 426.This will lock up relay 423 and escapement magnet 388 regardless of theground on wiper 412 as follows: .ground 427, wire 428, spring 429,spring 430, wire 431, spring 425, spring 426, wire 432 to wires 422 and421, which will keep relay 423 and escapement magnet 388 energized aslong asrelay 433 is energized. Relay 433 is energized as long as theswitch (Fig. 13) is connected with this trunk as follows: ground 367,wire 368, contact 366, wiper 347, wire 346, Wiper 345, contact 352, wire434, wire 435, wire 436, relay 433, Wire 437, wire 438, to battery 396.The energization of the relay 423 as a result of the ground upon theWiper 412 caused by its resting upon a contact associated with a busyline, closes the contacts 439 and 440, thus closing the followingcircuit through the calling substation: ground 441, wire secondarywinding 443, wire 444, spring 439, spring 440, wire 445, wire 387, wire3741. contact 372, wiper 370, wire 446, contact 365, wiper wire 334,wire 333, contact 307, wiper 305, wire 332, contact 287. wiper 274, wire273, wire 447, spring 448, spring 449, wire 450, condenser 451, wire226, wire 2119, contact 216, wiper 173, wire 174, contact 175, contact176, wire 177, wire 178, wire 1.61, terminal 150, wire 149, wire 148,coil 146, wire 144, contact spring 143, contact spring 151, contactspring 141, wire 1.40, transmitter 139, wire 179, spring 135, metalsegment 133, spring 136, wire 137, terminal 138, wire 162, wire 180,wire 181, spring 1.82, spring 183 wire 184, wipea 185-, contact 215,wire 218, wire 220, wire 221, winding 222, of relay 223, battery 225,ground 230. Induced impulses are'sent through the circuit just traced bymeansof the primary winding 452 inductively related to the secondarywinding 443, the circuit beingclosed periodically through such primarywinding .from battery 453 by means of a revolving commutator 454 asfollows: ground 441, wire 442, primary winding 452, wire 455, brush 456,commutator 454, brush 457, wire 458, battery 453 to ground. The impulsesthus transmitted through the apparatus at the calling substationindicate to the calling subscriber that the connection desired has beene'll'ccted but that the called subscribers line is busy.

Assume now that wipers 459, 460 and 412 have been moved to contacts 461.462 and 463 ,of an idle subscribers line. This closes a circuit fromground 464, wire 465, con tact 411, wiper 399, wire 413, wiper 412,contact 463, wire 466, wire 467, spring 468, spring 469. wire 470,cut-otl' relay 471, wire 472. wire 473 to battery 474. The energizationof this relay opens the lines 475 and 476 from any connection with theapparatu in Fig. 15 except the two normal wires 4'77 and 478. The calledsubscriber is now ready to be signaled. lmpulses sent out on line 376will now operate relay 479 as follows: ground on wire 376, spring 377.spring 378, wire 379, wiper 3 contact 408, wire 480, relay 479, wire 481to battery Relay 479 being a slow relay will remain operated during theimpulses and connect the generator to the called line as follows: brush482 of generator 483, wire 484, spring 485, spring 486. wire 487, wire488, wiper 397, contact 409, wire 489. wiper 459. contact 461., wire490, wire 475. wire 477, wire 491, post 492, wire 493. ringer 494,condenser 495, wires 496 and 497, post 498, wire 499, wire 478. wire476, wire 500, contact 462, wiper 460, wire 501, contact 410, wiper 398,wire 502, wire 508, spring 504, spring 505, wire 506, brush 507 ofgenerator 483, thus ringing the called subscriber. Vhen the calledsubscriber answers, he cuts his telephone across the two lines 490 and500 which will energize relay 508 as follows:

ground 509, wire 510, coil 511 of relay 508, wire spring 513, spring504, wire 503, wire 502, wiper 398, contact 410, wire 501, wiper 460,contact 462, wire 500, wire 476. wire 478, wire 499, post 498, wire 497,wire 514, spring 515, spring 516, wire 517, coil 518, wire 519,transmitter 520, wire 521, post 492, wire,491, wire 4'77, wire 47 .wire490, contact461, wi'cr 459, wire 489, contact 409, wiper 39 wire 488,wire 487, spring 486, spring 522, wire 523, coil 524 of relay'508, wire525, wire 385 to battery 383. The energization of this relay opens theenergizing circuit of the relay 47 9 by breaking contact between springs377 and 378 and connects line 376 through to the called line by closingthe contact between springs 877 and 526, wire 527 and wire 488 which, as

- has been shown, is connected to the called line. disconnected fromline 387 by breaking con tact between springs 390 and 391 and connectsline 387 to the called line by closing contact between springs 390 and528, wires 529 and 502 which, as has been shown, are connected to thecalled line.

The talking circuit as now set up is as follows: relay 223 is supplyingbattery to the calling subscriber and relay 508 is supplying battery tothe called subscriber. Commencing with line 180 one side of the talkingcircuit from the calling to the called subscr ber is as follows: line180, wire 181,

spring 182, spring 183, wire 184, wiper 185,

contact 215, wire 21-8, wire 220, wire 530, condenser 531, wire 532,spring 533, spring 534, wire 535, wire 253, wire 248, wiper 2149,contact 286, wire 308, wi er 304, contact 306, wire 309, wire 310, wiper311, contact 364, wire 536, Wiper 369, contact 371, wire wire 376,spring 377', spring 526, wire wire 488, wiper 397, contact 409, wire489, wiper 459, contact 461, wire 490, wire 475, wire 477, which isconnected to the called line. The other side of the talking circuit isasfollows: Wire 178, wire 177, spring 17 6, spring 175, wire 174, wiper173, contact 216, wire 219, wire 226, condenser .451, wire 450, spring449, spring 448, wire 447, wire 273, wiper 274, contact 287, wire 332,wiper 305, contact 307, wire 333, wire 334, wiper 335, contact 365, wire446, wiper 370, contact 372, wire'374, wire 387, wire spring 390, spring528, wire 529, wire 502, wiper 398, contact 410, wire 501, wiper 460,contact 462, wire 500, wire 476, wire 478 to the called subscribersline. The only 0 oration now is the release which on all t e switchesexcept the trunk selector is accomplished over local circuits. When theAlso the escapement magnet 388 is cal-ling subscriber hangs up hisreceiver, the trunk selector and the first selector are the firstswitches to release and the releasing circuits of these two switches areas follows: The hanging up of the calling subscribers receiverdeenergizes relays 223 and 23-8 and allows their armatures to return tonormal position, thus closing the following circuits: ground 235, wire236, spring 231, spring 233, wire 246, spring 242, spring 243, wire 537,wire 538, off normal spring 539, oil normal spring 540, wire 541, wire542, release magnet 543, wire 544, wire to battery 266. This willenergize release magnet 543 which will remain energized until shaft 267reaches its normal position and opens the contact between springs 539and 540. At the same time a circuit is closed in parallel to the lastcircuit as follows: wire 537, wire 538, wire 545, wire 546, contact 217,wiper 209, wire 214, wire 213, wire 188, release magent 124, wire 190,spring 191, spring 19" wire 193,

wire 194, to battery 195, thus energizing release magnet 124 which willremain energized as follows until wipers 185, 173 and 209 return totheir normal position: ground 547', wire 548, wire 549, oil normalspring 550, 09' normal spring 551, W113 552, spring 197, spring 553,which are thrown into con tact by the armature of release magnet 124,wire 547, wire 213, wire 188, release magnet 124, wire 190, spring 191,spring 192, Wire 1933, wire 194 to battery 195, thus locking up therelay until the switch has resumed its normal position and opened thecontact between springs 551 and 550.

Whenthe first selector is operated and wiper 289 is placed upon contact290', the following circuit is closed: ground 554, wire 555, contact288, wiper 285, wire 291, W116): 289, contact 1290, wire 556, wire 557,relay 558, wire 559, wire 560, wire 561 to battery 344, thus holding thesprings 562 and 563 on relay 558 out of contact until the first selectoris released and relay 558 deiiner gized. iVith relay 558 de'cinergized,the following release circuit for the second selector is closed: ground353, wire 354, wire 564, spring 562, spring 563, wire 565, 011' normalspring 566, oli normal spring 567, wire 568, wire 569, release magnet570, wire 571, wire 561 to'battcry 344, thus energizing release magnet570 until the shaft 329 returns to normal position and opens contactbetween springs 566 and 567.

Relay 433 is energized during the operae tion of the connector asfollows: round 367, wire 368, contact 366, wiper34t, wire 346, wiper345, contact 352, wire 434, wire 435, wire 436, relay 433, wire 437,wire 438 to battery 396. When the second selector is released, relay 433will allow spring 429 to make contact with spring 572' thus closing thefollowing release circuit: ground 427, wire 428, spring 429, spring 572,wire 573,

spring 574, spring 575, wire 576, wire 577, release magnet 5T8, Wire579, wire 4:38 to battery 396, thus energizing release magnet 578 untilshaft 386 574 and 57 5.

The connector will not be released in case the called subscriber has nothung up his receiver. In this instance the circuit for the release relaywill remain energized. This circuit may be traced from ground, lead 580,springs 581 and 582, lead 583, lead 436, relay 433, lead 437, lead 438to battery 396. This circuit will remain closed as long as the bridgedrelay 508 remains actuated. When the called subscriber replaces hisreceiver on the hook, the subscribers loop will be opened and thebridged relay 508 will be denergized. The consequent retraction of itsarmatures will open the circuit at-the contacts 581 and 582 andthereupon the release relay 433 will be denergized, which in turn willdenergize the release magnet 578 and thus restore the connector switchto normal. In the first selector, second selector'and con nector, theauxiliary release magnets 584, 586 and 587 are in multiple with theswitch release magnets 543, 570 and 57 8 so that the auxiliary switchwipers are also returned to normal position.

While I have shown my invention in the particular embodimenthereindescribed, I donot, however, desire to limit myself to this exactconstruction, but desire to claim broadly any equivalent that maysuggest itself to those skilled in the art.

What I claim is:

1. In an automatic combination of automatic switching mechanisms, trunkvoice current conductors,'a side switch for controlling the connectionof the actuating devices of the switching mechanism to such conductors,releasing devices for said switching mechanisms, independent releasingdevices for said side switches, and a trunk conductor independent of thevoice current conductors over which the releasing device of one sideswitch is controlled from the preceding side switch.

2. In anautomatic telephone system, the combination with a plurality ofswitches in a built up circuit, of bridging magnets at two of saidswitches, of each of said switches,

the release of the second switch depending upon the denergizareaches itsnormal position and opens the contact between springs switch and theswitch telephone system, the

release relays at tion of its release relay, said relay being under thecontrol of the bridging magnet at the first switch unless the bridgingmagnet at the second switch is actuated and the release of the firstswitch being independent of the bridging magnet of the second switch.

3. In an automatic telephone system, the combination with a pair oftelephone lines connected for conversation, of a plurality of switchesassociated with said connected circuit, release relays at each of saidswitches, means to energize said release relays when. the switches aretaken for use, a pair of bridges. across said circuit located atdifierent switches, one or more intervening switches free from bridgedelectromagnets, the release of the switches depending upon thedeenergization of their release relays, means whereby the bridge nearestthe cal ing subscribers station controls the release of all swltchesintervening between said bridge.

4. In an automatic telephone system, the combination with a built-upcircuit, of a plurality of switches through the contacts of which saidcircuit is maintained, a releasing relay for each of said switches,means to energize said release relays when the switches are taken foruse, the release of each switch depending upon the denergization of itsrelease relay, controlling magnets located at two of said switches, thecontrolling magnets of the switch nearest the calling subscribersstation controlling the release relays of sue ceeding switches with theexception of the other switch having controlling magnets.

5. In an automatic telephone system, a selector switch and a connectorswitch in a built up circuit, arelease relayfor the con-- nector switchhaving its circuit closed in two branches, one branch controlled by thecalling subscriber through said selector switch and the other branchcontrolled by the called subscriber through said connector switch, therelease of said'connector switch being effected by the deenergization ofsaid release relay.

In witness whereof, I hereunto subscribe my name this 30 day of June, A.D. 1910.

RAY s. winnnn.

Witnesses:

G. B. Knrsnn, ALFRED A. FRANoK.

semen at ttita patent may he obtatncd for flue cents each, by addressingthe commissioner oi ratenta,

' Washington, D. t2.

containing the other

